ROTC/SMP or Usmma for AD

Hello. I am a sponsored prep at Nmmi for the Merchant Marine Academy but I am debating switching to Rotc at a college near my home. More than anything I want active duty and doing more research I am finding that I might have a better chance through rotc than the academy because I know for sure my gpa would go down at the academy. I am on Ranger Challenge and have no pt problems. The college im looking at has at lowest 75% AD commisoning rate. What do you think would be my best option? Unlike other academies you have to apply for AD at usmma.